Printing multicolored three-dimensional products

ABSTRACT

A method and apparatus are provided for printing multicolored three-dimensional objects. The method includes: selectively exposing a photosensitive thermoplastic feedstock to light within an extrusion nozzle, the feedstock comprising a thermoplastic base mixed with a photosensitive material; extruding the exposed feedstock into a deposit to print an object; and photo-chemically developing the deposit to provide color to the deposit. An apparatus is provided for three-dimensional printing with an extrusion nozzle including a light exposing component for selectively exposing the photosensitive thermoplastic feedstock to light within the extrusion nozzle.

This application is a continuation application claiming priority to Ser.No. 15/470,013, filed Mar. 27, 2017.

TECHNICAL FIELD

The present invention relates to printing multicolored three-dimensionalproducts, and more specifically, to multicolored Fused DepositionModeling using photosensitive plastic feedstock.

BACKGROUND

Fused Deposition Modeling (FDM) (Fused Deposition Modeling and FDM aretrademarks of Stratasys Inc.) is a manufacturing technology forthree-dimensional printing by laying down material in layers in the formof a plastic filament from a nozzle ejecting molten material. Thisthree-dimensional printing technique is also referred to as FusedFilament Fabrication (FFF) or Plastic Jet Printing (PJP).

SUMMARY

An apparatus and method of printing multicolored three-dimensionalobjects is provided. The method includes selectively exposing aphotosensitive thermoplastic feedstock to light within an extrusionnozzle, the photosensitive thermoplastic feedstock comprising athermoplastic base mixed with a photosensitive material, extruding theexposed feedstock into a deposit to print an object, andphoto-chemically developing the deposit to provide color to the deposit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of an example embodiment of a method ofprinting multicolored three-dimensional objects, in accordance withembodiments of the present invention.

FIG. 2 is a block diagram of an example embodiment of a printingapparatus, in accordance with embodiments of the present invention.

FIG. 3 is a cross section view of a printing apparatus, in accordancewith embodiments of the present invention.

FIG. 4 depicts a block diagram of a computing system capable ofimplementing the printing of multicolored three-dimensional objects, inaccordance with embodiments of the present invention.

DETAILED DESCRIPTION

The FFF and PJP types of three-dimensional printers have limitedcolor-printing capabilities. Multi-material printing is known throughdifferent nozzles through which different colors of feedstock materialmay be used, which is restricted to a number of fixed colors equal tothe number of materials the printer can take in. Multi-material mixingthrough one nozzle is known in which machines produce a mixture ofdifferent colors of material. Thorough mixing is difficult to achievedue to the difficulties of sufficiently mixing the filament whilekeeping the melt zone as short as possible for good extrusion response.Mixing of colorant with the extruded material is another known techniqueand these machines suffer similar mixing issues as with multi-materialmixing.

According to an aspect of the present invention there is provided amethod of printing multicolored three-dimensional objects, the methodcomprising: selectively exposing a photosensitive thermoplasticfeedstock to light within an extrusion nozzle, the feedstock comprisinga thermoplastic base mixed with a photosensitive material; extruding theexposed feedstock into a deposit to print an object; andphoto-chemically developing the deposit to provide color to the deposit.

According to another aspect of the present invention there is providedan apparatus for printing multicolored three-dimensional objects usingan extruded feedstock to print an object, comprising: a feedstock inputcomponent for receiving a feedstock comprising a thermoplastic basemixed with a photosensitive material which is kept removed from exposedto light; an extrusion nozzle for extruding the exposed feedstock into adeposit to print the object and a light exposing component forselectively exposing the photosensitive thermoplastic feedstock to lightwithin the extrusion nozzle; and a developing component forphoto-chemically developing the deposit to provide color to the deposit.

According to a further aspect of the present invention there is provideda computer-implemented method for controlling printing multicoloredthree-dimensional objects, comprising: controlling an exposure of thephotosensitive thermoplastic feedstock to light within an extrusionnozzle by a plurality of light sources of different colors in a requiredproportional intensity for a required resultant color; and controllingthe color by mapping a desired color to the light source exposure of theplurality of light sources for a required portion of the deposit.

The described process and apparatus provide a photosensitivethermoplastic feedstock to a modified three-dimensional (3D) printingapparatus, which is extruded through a modified nozzle where it isexposed to colored light, possibly internally to the nozzle. The printeddeposit or part is photo-chemically developed to result in a highresolution full color part using a process similar to that used inphotography.

The modified printing apparatus uses FDM technology and conventionallybegins with a software process that processes a digitalthree-dimensional model, mathematically slicing and orienting the modelfor the build process. If required, support structures may be generated.

The apparatus may dispense multiple materials to achieve differentgoals. For example, a first material may be used to build up the modeland another material used as a soluble support structure.

The deposit or printed part is produced by extruding small, flattenedstrings of molten material to form layers as the material hardens afterextrusion from the nozzle. The feedstock may be a plastic filament thatis unwound from a coil or provided as granulated particles and suppliedto an extrusion nozzle that can turn the flow on and off. A drivemechanism pushes the feedstock into the nozzle at a controlled rate.

Thermoplastic materials used as feedstock are heated by the nozzle tomelt the material past their glass transition temperature and the moltenmaterial is then deposited by an extrusion head.

The nozzle can be moved in both horizontal and vertical directions by anumerically controlled mechanism. The nozzle follows a tool-pathcontrolled by a computer-aided manufacturing (CAM) software package, andthe part is generally built from the bottom up, one layer at a time.Stepper motors or servomotors are typically employed to move theextrusion head. The mechanism used is often an X-Y-Z rectilinear design,although other mechanical designs such as delta robot may be employed.

Various feedstock materials are available with different trade-offsbetween strength and temperature properties, such as AcrylonitrileButadiene Styrene (ABS), Polylactic acid (PLA), Polycarbonate (PC),Polyamide (PA), Polystyrene (PS), lignin, rubber, among many others.

During FDM process, the hot molten polymer is exposed to air. Operatingthe FDM process within an inert gas atmosphere such as nitrogen or argoncan significantly increase the layer adhesion and leads to improvedmechanical properties of the 3D printed objects.

The described process and apparatus provide a photosensitivethermoplastic feedstock to a modified FDM apparatus. The FDM apparatusis modified to include a nozzle that provides selective light exposureto the feedstock as it is extruded, thereby activating thephotosensitive material in the feedstock. The printed deposit is thenphoto-chemically developed to result in a high resolution full colorprinted part.

Photo-reagent chemicals may be included in the feedstock itself, whichmay be, for example, a thermoplastic filament or granulated particles.

A feedstock may use a regular thermoplastic base, for example, PolyLactic-Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), or Nylon mixedwith a photosensitive material. Photosensitive materials may include,for example, silver halides emulsions including dye couplers that incombination with processing chemistry, form visible dyes. When colordeveloper reduces exposed silver halide crystals, the developer isoxidized and the oxidized molecules react with the dye coupler moleculesto form dye in the material. The feedstock may include approximately 1%to 10% by mass of a colorant formed of silver halide emulsion includingdye couplers. Off-the-shelf silver halide emulsions may be used asprovided by various manufacturers.

A neutral color existing thermoplastic feedstock such as PolyLactic-Acid (PLA) filament or particle feedstock may be produced indark-room conditions or a dark enclosed adaptation of existingprocesses.

In one specific example embodiment, the PLA feedstock may include 1% to10% by mass of a colorant formed of silver halide emulsion including dyecouplers (10 parts), ammonium thiosulphate (8 parts), and ferricammonium EDTA (1 part). This embodiment is based on the Kodak RA-4process (Kodak and RA-4 are trademarks of Eastman Kodak Company). Otherformulations of the described colorant can be used with other colorantprocesses.

The thermoplastic feedstock contains silver halide emulsions sensitiveto different wavelengths of light, usually three wavelengths, forexample: cyan, magenta, and yellow. Cyan-colored dye is formed on thered-sensitive layer, magenta-colored dye is formed on thegreen-sensitive layer, and yellow-colored dye is formed on theblue-sensitive layer, following generally the CMY color model. There isalready a very mature, sophisticated and industrial body of chemistryfor this photo-chemical process, for example, chromogenic color printfilm developing processes such as C-41, K-16 and E-6, and the materialsscience of robustly embedding the dye into a film substrate used for,for example, 35 mm film.

Once produced, the color-feedstock may be contained in an opaque vesselto facilitate transportation outside of dark-room conditions or theenclosed manufacturing equipment. Such a feedstock would be kept incomplete darkness, like a camera film, which may be achieved by using afilament cartridge system that is plugged into the extruder of theapparatus. For instance, a roll of filament in a box with an apertureperforated at the point of use to allow the filament to be extractedinto the 3D printer.

The apparatus nozzle is adapted such as the channeled feedstock passes aplurality light sources such as electronically lit windows in directcontact with the channeled feedstock before the feedstock leaves thenozzle as extrudate.

In an embodiment in which the feedstock is a filament, the light sourcesmay be applied to a strand of the filament before, during or after theheating process. The filament may be stretched to a thinner diameterduring the heating process, enabling deeper distribution of the lightsources within the filament.

In an embodiment in which the feedstock is of granulated form, the lightsources may be applied during or after the melting process whilst thefeedstock is within a channel or tube such as the extruding nozzle.

Multiple windows may be provided with one window for each color oflight, for example, three windows for cyan, magenta and yellow lightsources.

If desired, the ports of entry for the light into the feedstock nozzlemay be replicated around the circumference of the feedstock tube toprovide an even exposure of the ‘external’ surface of the feedstock tothe light, which may be achieved by multiple windows for each colorbeing distributed in a repeating pattern around the nozzle.

The light may be applied to the feedstock at right angles to thefeedstock tube's axis to decrease the width of the exposing effect andthus increase the resolution.

The colors of lights used to expose the feedstock may depend on thephotosensitive material used. The colors of lights are not necessarilythe natural colors and may be the color negative of the desired result.

The color intensities may be set so as to expose the passing feedstockappropriately to form the desired color for the position that theextruded feedstock will be laid onto the deposit, which requires amapping of desired color to exposure color. The color of light thefeedstock is exposed to is a negative in the described process, withcyan set as a lower intensity as the feedstock is more sensitive. Sothere is a mapping of desired colour/brightness on one side, andexposure colour/brightness on the other. Other quantities and colors oflights may be used with bias of intensity varied to achieve desiredresults.

The light sources may be any selected multiple wavelengths of light, orany other means, that activate separately, three 3-colour pigments suchas red-green-blue or cyan-magenta-yellow to different degrees that canthen be developed later to give the impression of true color (i.e. anytone from a possible range on the spectrum in the plastic).

The feedstock may need to be exposed for the color of the part of themodel due to be printed in a short time. The part of the model that theexposed extruded feedstock will form is predictable due to the knownvolume of the hot end and known volume of the “tracks” to be printed.

A cost improvement may be gained by using the already known technique ofusing a dual nozzle printer to print different parts of the object withdifferent feedstock, for example, only using a photosensitive feedstockfor the outer layer or layers.

As the extruded feedstock is very thin at the hot end of the extruderand slightly translucent, the light illuminates the extruded feedstockexternally and internally with good coverage to expose the extrudedfeedstock fully, eliminating the need for post exposure mixing. As avery small amount of light is used and as the light travels a very smalldistance within a small tube, the feedstock does not need to betransparent, only translucent to allow the light exposure to occur atthe correct levels. A level of opaqueness when solid may be desirable toprevent the light passing within the extruded feedstock like afiber-optic cable.

The small diameter of the extruded feedstock that is being exposedminimizes the distance the light has to travel to reach the center ofthe extruded feedstock. The distance is shorter than that appropriatefor the translucency of the material to allow the feedstock to besaturated with light of the correct relative weightings more or lessevenly in cross section.

Additionally, as the feedstock may be made to be more or less equallytranslucent to the three colors of light used, any small ramp inexposure towards the center of the extruded feedstock will both be interms of color saturation rather than producing a different color. Also,feedstock material in the center of the extruded feedstock is not aslikely to be on the external surface of the printed part and vice versa.

Using existing photosensitive materials, a color space recognizable as“full-color” and with varying gradient can be achieved.

The 3D printer may otherwise be a standard Fused Deposition Modeling(FDM) type printer in dark-room conditions or fully surrounded with anopaque enclosure. Once the color-feedstock is loaded into the printer, aprint shall be formed using the standard process constructing either allof the part, or just the outer shell of the part from thecolor-feedstock, in the latter case the rest of the part may be formedof standard feedstock using an existing multi-extrusion method.

The sensitive but ‘unfixed’ portion of the printed part is eitherprinted in darkness or illuminated with the equivalent of a darkroomstyle ‘red’ light that does not affect the material. Once complete, theprinted part may be kept in dark-room conditions or inside the enclosureof the machine.

The developer causes the outer shell of the printed part to develop thedesired color that can then be set. The fix stage of traditionalphotographic development is required to stop further development of thecolor.

Some developers can be removed by simply washing with a solvent, such aswater, to remove the development chemical; others may require a specificchemical to neutralize the development reaction (e.g. often these arealkali/basic). Delivery by washing may be achieved as some of thefilaments for 3D printing are porous. Immersion or spraying with the fixcould be used. Alternatively, if the fix's chemical properties permitteddelivery may be in a gaseous form.

In one embodiment, the part may be moved to a bath where the part can berinsed under or submerged in a developer formed of water (750 parts),triethanolamine (6 parts), sodium sulfite (1 part), color developerformula 3 (CD-3) (5 parts), potassium carbonate (40 parts) and sodiumchloride (½ a part). The printed part may be developed for approximately1 minute then rinsed with clean water until free from developer. Otherchemical developers, different formulae and processing times may beused.

The printed part may then be rinsed in dilute acetic acid (1%) to fixthe color, and then clean water to wash off the acetic acid fixer. Otherfixing agents or other existing processes may be used.

The printed part may be removed from the apparatus's enclosure asdark-room conditions are no longer required. Once dry, the printingprocess is complete.

In another embodiment, the feedstock may have embedded within thefeedstock micro-capsules containing the fix, which may enable thefeedstock to be non-porous as feedstock will not need to be washed tofix the color. The feedstock micro-particles ordinarily would be dormantthrough most of the processes and may be activated or released whenneeded. Two methods for approaching this would be to have a heat ramp orsecond heating element to melt the micro-capsules that would need ahigher melt point or to use targeted ultrasound to break these open.

Referring now to the drawings, FIG. 1 is a flow diagram of an exampleembodiment of a method of printing multicolored three-dimensionalobjects, in accordance with embodiments of the present invention. Flowdiagram 100 shows an example embodiment of the described process.

Feedstock is provided at step 101 in the form of a thermoplastic basemixed with photosensitive material. The photosensitive material mayinclude a silver halides emulsion with dye couplers and dye developer.The photosensitive material when exposed to differing amounts of coloredlight combinations forms visible dyes to the thermoplastic base.

The feedstock is kept removed at step 102 from external light and inputto the printing apparatus. The printing apparatus is a FDM apparatuswith an extrusion nozzle through which the feedstock is driven at step103.

The extrusion nozzle is modified to include multiple light sources andthe feedstock is selectively exposed at step 104 to light from themultiple light sources to result in the required colors to be applied tothe extruded feedstock. The process may control the selective exposureby mapping a desired color to the light sources for a part of an objectbeing printed, at step 105.

The light exposure at step 104 may be during or at the end of theextrusion of the feedstock and the light exposed feedstock may beextruded at step 106 into a deposit to print the object. The object maybe photo-chemically developed and fixed 107 to finalize and fix thecolor.

Referring to FIG. 2, a block diagram shows an example embodiment of theprinting apparatus 200, in accordance with embodiments of the presentinvention. A printing apparatus 200 in the form of a FDM apparatus isprovided and operated in a dark-room enclosure 210 or under dark-roomconditions.

The printing apparatus 200 may include a printing control component 204that may be run on a computer system such that a controlling computerprogram can operate the printing apparatus. The printing controlcomponent 204 may include at least one processor 241, a hardware module,or a circuit for executing the functions of the described componentswhich may be software units executing on the at least one processor.Memory 242 may be configured to provide computer instructions 243 to theat least one processor 241 to carry out the functionality of theprinting control.

The printing apparatus 200 may include a feedstock input component 202which may be in the form of a cartridge that may be plugged into anextrusion component 220 of the printing apparatus 200. The extrusioncomponent 220 may include a feedstock drive component 222 for drivingthe feedstock to an extrusion nozzle 221 which may be heated by aheating component 223.

The extrusion component 220 may be provided in association with a lightexposing component 230 for providing light through the sides of theextrusion nozzle 221, for example, by means of light sources 231adjacent windows in the extrusion nozzle 221.

A color control component 240 may be provided which may be incorporatedinto the printing control component 204 that controls the movement ofthe extrusion nozzle 221. The color control component 240 may include anexposure controlling component 245 for controlling the intensity andduration of the light sources 231 under control of a mapping component246 which maps a desired color to a part being printed.

The printing apparatus 200 may include a developing component 250 fordeveloping the color of the photosensitive material in the extrudedfeedstock and fixing the color, which may be a bath or a series of bathsof the developing and fixing chemicals in liquid form into which theextruded object may be placed. Alternatively, this may be a spraycompartment for delivering the developing and fixing chemicals ingaseous form.

FIG. 3 depicts a schematic cross-section 300 of a portion of theprinting apparatus, in accordance with embodiments of the presentinvention. The portion of the printing apparatus shows the extrusioncomponent that has a hot end 304 with a heat break 302 surrounding aninput funnel 303 to the extrusion nozzle 305. A heating element 306applies heat to the extrusion nozzle 305 and a thermistor may beprovided in a recess 316 to measure the nozzle temperature for theheating control loop.

The hot end 304 receives the feedstock, for example, as a filament, fromthe extruder via the heat break 302. In an exemplary embodiment, theheat break 302 may have a diameter of approximately 1.75 to 3.00 mm. Theheating element 306 melts the filament, which progresses down thenarrower section in the form of the extrusion nozzle 305 of the hot end.The extrusion nozzle 305 may have a diameter of approximately 0.1 to 0.6mm.

Light sources of several colors 310, for example light emitting diodes(LEDs), illuminate the filament through glass light pipes 314 to exposethe photosensitive material in the filament. The transparency of thefilament is such that the light is able to penetrate the fraction of amillimeter diameter of the molten filament here, but such that excessivelight cannot travel the few millimeters to the nozzle opening and theprinted part 308.

The extruded feedstock 307 is laid in a controlled pattern to form aprinted part 308 of an object, which is then processed by anotherportion of the apparatus to develop and fix the color.

The light sources 310 may have at least three colors 311, 312, 313. Thelight pipes 314 may supply the light to the extrusion nozzle 305 suchthat the light is emitted perpendicularly into the nozzle 305. The lightpipes 314 may be arranged such that each color is delivered in acircumferential spacing around the nozzle 305.

FIG. 4 depicts a block diagram of a computing system capable ofimplementing the printing of multicolored three-dimensional objects, inaccordance with embodiments of the present invention. A schematic of anexample of a system 400 in the form of a computer system or server isshown which may be provided in communication with the described printingapparatus for control of the printing apparatus including the colorcontrol.

A computer system or server 412 may be operational with numerous othergeneral purpose or special purpose computing system environments orconfigurations. Examples of well-known computing systems, environments,and/or configurations that may be suitable for use with computersystem/server 412 include, but are not limited to, personal computersystems, server computer systems, thin clients, thick clients, hand-heldor laptop devices, multiprocessor systems, microprocessor-based systems,set top boxes, programmable consumer electronics, network PCs,minicomputer systems, mainframe computer systems, and distributed cloudcomputing environments that include any of the above systems or devices,and the like.

Computer system/server 412 may be described in the general context ofcomputer system-executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 412 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

In FIG. 4, a computer system/server 412 is shown in the form of ageneral-purpose computing device. The components of the computersystem/server 412 may include, but are not limited to, one or moreprocessors or processing units 416, a system memory 428, and a bus 418that couples various system components including system memory 428 toprocessor 416.

Bus 418 represents one or more of any of several types of busstructures, including a memory bus or memory controller, a peripheralbus, an accelerated graphics port, and a processor or local bus usingany of a variety of bus architectures. By way of example, and notlimitation, such architectures include Industry Standard Architecture(ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA)bus, Video Electronics Standards Association (VESA) local bus, andPeripheral Component Interconnects (PCI) bus.

Computer system/server 412 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 412, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 428 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 430 and/or cachememory 432. Computer system/server 412 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 434 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 418 by one or more datamedia interfaces. As will be further depicted and described below,memory 428 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

Program/utility 440, having a set (at least one) of program modules 442,may be stored in memory 428 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 442 generally carry out the functionsand/or methodologies of embodiments of the invention as describedherein.

Computer system/server 412 may also communicate with one or moreexternal devices 414 such as a keyboard, a pointing device, a display424, etc.; one or more devices that enable a user to interact withcomputer system/server 412; and/or any devices (e.g., network card,modem, etc.) that enable computer system/server 412 to communicate withone or more other computing devices. Such communication can occur viaInput/Output (I/O) interfaces 422. Still yet, computer system/server 412can communicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 420. As depicted, network adapter 420communicates with the other components of computer system/server 412 viabus 418. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 412. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

In the context of the present application, where embodiments of thepresent invention constitute a method, it should be understood that sucha method is a process for execution by a computer, i.e. is acomputer-implementable method. The various steps of the method thereforereflect various parts of a computer program, e.g. various parts of oneor more algorithms.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The present invention may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instructions by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

In one embodiment, the system of the present invention may be or includea hardware device such as a computer, portable device, etc. In oneembodiment, the hardware device is or includes a special-purpose device(e.g., computer, machine, portable device) that comprises specialized,non-generic hardware and circuitry (i.e., specialized discretenon-generic analog, digital, and logic based circuitry) for(independently or in combination) particularized for executing onlymethods of the present invention. The specialized discrete non-genericanalog, digital, and logic based circuitry may include proprietaryspecially designed components (e.g., a specialized integrated circuit,such as for example an Application Specific Integrated Circuit (ASIC),designed for only implementing methods of the present invention).

A computer program product of the present invention may include one ormore computer readable hardware storage devices having computer readableprogram code stored therein, said program code containing instructionsexecutable by one or more processors of a computing system (or computersystem) to implement the methods of the present invention.

A computer system of the present invention may include one or moreprocessors, one or more memories, and one or more computer readablehardware storage devices, said one or more hardware storage devicescontaining program code executable by the one or more processors via theone or more memories to implement the methods of the present invention.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

Improvements and modifications can be made to the foregoing withoutdeparting from the scope of the present invention.

What is claimed is:
 1. An apparatus for printing multicoloredthree-dimensional objects using an extruded feedstock to print anobject, comprising: a feedstock input component for receiving afeedstock comprising a thermoplastic base mixed with a photosensitivematerial which is kept removed from exposure to light; an extrusionnozzle for extruding an exposed feedstock into a deposit to print theobject and a light exposing component for selectively exposing thephotosensitive thermoplastic feedstock to light within the extrusionnozzle; and a developing component for photo-chemically developing thedeposit to provide color to the deposit.
 2. The apparatus as claimed inclaim 1, wherein the developing component for photo-chemicallydeveloping the deposit to provide color to the deposit includes applyinga fluid including a chemical developer and rinsing or stopping theapplication after a predetermined time.
 3. The apparatus as claimed inclaim 1, wherein the light exposing component selectively exposing thefeedstock to light within the extrusion nozzle provides a plurality oflight sources of different colors directly to the feedstock in thenozzle in a required proportional intensity for a required resultantcolor.
 4. The apparatus as claimed in claim 2, wherein the plurality oflight sources of different colors are applied substantiallyperpendicular to the direction of extrusion of the feedstock and spacedcircumferentially around the nozzle.
 5. The apparatus as claimed inclaim 3 including a control component having a processor and a memoryconfigured to provide computer program instructions to the processor toexecute the function of the control component, including: controlling,by the processor, the exposure of the feedstock to light within theextrusion nozzle by the plurality of light sources of different colorsin a required proportional intensity for a required resultant color; andcontrolling, by the processor, the color by mapping a desired color tothe light source exposure of the plurality of light sources for arequired portion of the deposit.
 6. The apparatus as claimed in claim 5,wherein controlling the color includes providing the color to only anouter shell portion of the deposit.
 7. A feedstock for printingmulticolored three-dimensional objects using an apparatus as claimed inclaim 1, wherein the feedstock is a partially transparent,thermoplastic-based filament including silver halide emulsions includingdye couplers.